Surgical procedures to address illness, disease or injury vary depending on a number of factors, including the ability of the surgeon(s) to access and perform the necessary procedures at the affected site. As one example, individuals who suffer degenerative disc disease, natural spine deformations, a herniated disc, spine injuries or other spine disorders often require surgery on the affected region to relieve pain or prevent further injury to the spine and nerves. Spinal surgery may involve removal of damaged joint tissue, insertion of a tissue implant and/or fixation of two or more adjacent vertebral bodies. These procedures are often difficult due to the location of the spine and adjacent nerves, sensitive anatomy, etc. The surgical procedure will vary in approach and duration depending on the nature and extent of the injury.
One particular type of spinal surgery is referred to as “fusion.” Fusion of vertebral bodies involves fixation of two or more adjacent vertebrae. This procedure may be performed through introduction of rods or plates, and screws or other devices into a vertebral joint to join various portions of a vertebra to a corresponding portion on an adjacent vertebra. Fusion may occur in the lumbar, interbody or cervical spine region of a patient. A fusion is designed to stop and/or eliminate all motion in the spinal segment by destruction of some or all of the joints in that segment and further utilizing bone graft material and/or rigid implantable fixation devices for securing the adjacent vertebrae. By eliminating movement, back pain and further degenerative disc disease may be reduced or avoided. Fusion requires tools for accessing the vertebrae, such as surgical cannulae for “minimally-invasive” surgical procedures, and other tools for implanting the desired implant, bioactive material, etc. Such procedures often require introduction of additional tools to prepare a site for implantation. These tools may include drills, drill guides, debridement tools, irrigation devices, vises, clamps, cannula, and other insertion/retraction tools.
Spinal surgeries may be performed by a number of different “minimally-invasive” procedures, as opposed to conventional surgical procedures and methods, which typically require cutting of muscles, removal of bone, and retraction of other natural elements. With minimally invasive spinal surgery, a less destructive approach to the spine is carried out by using portals, which take advantage of anatomy and current technology to limit the damage to intervening structures.
Typically, skeletal landmarks are established fluoroscopically and a small incision is made over the landmark(s). According to methods known in the prior art, a series of dilators are applied until one or more cannula is placed over the anatomic structure. A microscope is then placed over the operative site. The microscope provides illumination and magnification with a three dimensional view of the anatomical site. While this process provides substantial advantages relative to open surgery, it requires the use of an operating microscope. This particular piece of equipment is extremely expensive (most quality brands are in the $250,000 range). The microscope is an unwieldy device requiring uncomfortable gyrations of the surgeon's back and neck in order to gain the necessary view and is a nuisance to drape (a large, sterile plastic bag has to be placed over the eight foot tall structure). The illumination is also difficult to direct due to the size of the microscope.
A significant danger of performing intervertebral operations or accessing an intervertebral space during spine surgery is that of inadvertently contacting or damaging the para-spinal nerves, including the exiting nerve roots, traversing nerves and the nerves of the cauda equina. The exact location of these para-spinal nerves cannot be determined prior to the commencement of surgery, and therefore are dependent on a surgeon's ability to visually locate the same after the initial incision is made. Moreover, intervertebral spaces in the spine have other sensitive nerves disposed at locations which are not entirely predictable prior to insertion of the surgical tool into the intervertebral area. Accordingly, the danger of pinching or damaging spinal nerves when accessing an intervertebral space has proven to be quite limiting to the methods and devices used during minimally invasive spinal surgery. In addition, as cannula are received through the patient's back, such as when performing minimally invasive spinal surgery, minor blood vessels are ruptured, thereby blocking the surgeon's vision inside the intervertebral region after the cannula has been inserted. Other anatomical features at a particular patient may also destruct the surgeon's view or make it difficult to provide illumination within the cannula.
Lateral based spinal surgery is a known alternative to conventional surgical procedures, and is generally referred to as a “minimally-invasive” procedure. Lateral based procedures offer the advantages of shorter recovery times, reduced blood loss, reduced post-operative complications, and shorter operating times than conventional procedures and methods. For example, one surgical approach for spinal fusion using a minimally invasive technique is known as “lumbar interbody fusion” or LIF for short. Other known examples of lateral based approaches include the Nuvasive XLIF procedure and Medtronic D-LIF System. However, these systems and methods have problems and shortcomings, including, but not limited to, limited visualization and lighting in the surgical area, increased risk of impinging upon the nerves of the lumbosacral plexus, and the ilioinguinal and genitofemoral nerves and the risk of devices and/or instruments becoming dislodged during the various procedures, among others. These problems, alone or in combination, may result in post-operative pain and discomfort experienced by patients of lateral based spinal surgery. In some instances, these problems require or otherwise lead to additional surgeries, further complicating the likelihood of recovery and successful fusion.
Various devices and surgical access systems are known in the art to facilitate minimally invasive surgical procedures while allowing for a sufficiently large surgical area. These devices may include a series of tools which, when consecutively inserted, serve to gradually expand an area, including cannula. Retractors are useful for gradually dilating the area of an incision or surgical opening in order to form a desired amount of space within which various procedures may be conducted. Retractors may take the form of a single device that may be inserted into a work area and expanded at the direction of a user, thus allowing for the creation and maintaining of a surgical work space. Many retractors fail to provide independent illumination sources or allow the surgeon to visualize the path of access to the surgical site. As these retractors are often the first (or one of the first) tools used in the procedure, providing adequate illumination and enhancing visualization are important to the success of the operation. Thus, there is a present felt need for an improved retractor with enhanced illumination that otherwise improves the visibility for the surgeon, and for a method of retrofitting an existing retractor with apparatus to accomplish this objective.
Other problems experienced in minimally invasive surgical procedures include the risk of injury caused during the initial probing and dissecting of tissue between the incision and the surgical site. Typically, such probing is done using a finger or a slender dilator or other tool, which is used to navigate through the soft tissue, anatomy, and ultimately reach the desired point of access to the surgical site. During this probing, there is increased risk to injury to the lumbar plexus, particularly when the surgeon is attempting to access the lumbar spine. In addition, there is also an increased risk to the patient's anatomy, and to undesired dissection of various anatomical features between the incision and the surgical site. This risk of injury typically increases as the probe is inserted deeper into the body of a patient, and continues after the probe has been fully inserted and continuing through dilation, such as by inserting one or more progressive surgical cannula around the dilator proceeds. Damage to the peritoneal membrane, colon perforation, ureteral or great vessel injury can be the result of the “blind” dissection and is major reason why the lateral, transpoas approach is not a more commonly performed surgical procedure. Thus, there is a deep felt need in the art to mitigate these potentially catastrophic complications, and to address the other problems associated with performing these procedures in a “blind” manner.
Typically, as these processes for accessing the surgical site are done blind (i.e., without vision of where the probe is directed), it is not uncommon that the probing instrument(s) intersect and/or dissect the patient's anatomy, intercept nerves, sensitive tissue, rupture arteries, etc. Thus, there is also a need for an improved tool for initially dilating and accessing the tissue between the incision and the surgical site. There is a further need for an improved system and method for providing a surgeon with visibility of this area, to assist with the navigation through the tissue, anatomy, etc. and to provide enhanced illumination for a minimally invasive surgical procedure.
The disclosure of the invention herein addresses these and other problems by providing a system and method for achieving an endoscopic approach to a surgical site, coupled with the use of a unique illumination and video capability. The system of the invention is preferably achieved by incorporating a camera chip in the apparatus of the system, thereby obviating the need and disadvantages of the operating microscope and other expensive and cumbersome instrumentation. These and other considerations are addressed by the present disclosure in more detail in the Summary and Detailed Description.